INCOME TAXES - Unrecognized Tax Benefit Activity (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the period	$ 7,237	$ 4,739	$ 3,257
Additions related to prior year tax positions	120	2,019	420
Additions related to current year tax positions	1,600	610	2,053
Reductions related to prior year tax positions	(453)	0	0
Reductions related to settlements with taxing authorities	(436)	(131)	0
Reductions related to expiration of the applicable statute of limitations	(1,493)	0	(991)
Balance at the end of the period	$ 6,575	$ 7,237	$ 4,739

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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